Should I encourage my son to continue with rugby ?

I have a 9 year old son who has played rugby for a couple of years. He also does football and is better at rugby than football. He is doing both at the moment Football Sat and Rugby Sunday - he says he doesnt want to continue rugby next season - altho when he goes to rugby he enjoys it, has a great laugh with the other boys, and always finishes with a big grin on his face, and having fun with the others.

Issues are1. He prefers football to rugby - and definitely wants to continue with that next season2. It means sport both Sat and Sun morning - he is inclined to idleness so do I encourage him to continue both next season to ensure he is getting plenty of exercise ? Exercise at school is woeful.3. Do I let him have a veg/quiet day at the weekend (I have to admit I wouldnt mind a day not stood on a cold touchline)4. I wish I had been encouraged to be more active as a child (was always a bit overweight) - son is in good proportion - but its still a concern that if he drops some activity he may become overweight (he has a very healthy apetite but fortunately like healthy food)

He has some academic learning difficulties (dyslexia and dyscalula) so really want him to enjoy and do well in a sport for his confidence.Hope you dont think I am a pushy parent but I just dont know what to do for the best.